Dendritic cells (DCs) are the sentinels of the immune system. They mature at the encounter of the appropriate stimuli or danger signals, which induce them to perform pro-inflammatory antigen presentation to naïve and memory T cells, resulting in inflammation. Remaining in an immature state however, DCs acquire a tolerogenic phenotype. When activated by TLR ligands, DCs undergo metabolic re-programming and switch to TBK1/IKKe/AKT-induced glycolysis at the early activation phase, which is sustained due to nitric oxide (NO)-mediated inhibition of mitochondrial metabolism at the later activation phase. Targeting DC activation in the view of promoting less activated or tolerogenic DCs could be an approach to reduce or abrogate inflammation in settings such as solid organ transplant rejection or in autoimmune diseases such as systemic lupus erythematosus (SLE). In this thesis, we present data pertaining to three different approaches for targeting DC activation including 1) the use of ethyl p / Microbiology and Immunology

The speed of a chemical reaction is important in determining the efficiency of many industrial chemical reactions. In organic reactions particularly, when there is the possibility of several reactions going on simultaneously, that reaction which is fastest is the one that predominates and often affects the economics of the process. The object of this investigation was to determine the effect of ultrasonic irradiation on the specific reaction rate of the hydrolysis of an aqueous solution of ethyl acetate in the presence of hydrochloric acid as the catalyst. The commercially obtained ultrasonic generator was limited to four frequencies - namely, 400, 700, 1000, and 1500 kilocycles. Two thousand volts plate voltage could be applied to the quartz crystal plates provided the plate current did not exceed 360 milliamperes. A special pyrex glass reactor was designed and constructed in order that isothermal conditions could be maintained within the boundary of the reactor. The period of time the reaction mixture was subjected to ultrasonic irradiation was arbitrarily set at 10 minutes for a given power and frequency at 19 ± 0.1°C and 30 ± 0.1°C respectively. The tests were then repeated using a 20 minute period of irradiation. Individual mixtures were respectively irradiated at 0, 500, 1000, and 1500 volts plate voltage. The composition and volume of the mixture irradiated was 100 ml of 1.9904 N hydrochloric acid, 90 ml of distilled water free from carbon dioxide, and 10 ml of ethyl acetate making a total volume of 200 ml. The chemical reaction assumed for the investigation was CH₃COOC₂H₅ + H₂O + H⁺ ⇋ CH₃COOH + C₂H₅OH + H⁺ The course of the reaction was followed in such a way that the concentrations of the reacting substances were not disturbed. Samples of the mixture were drawn off at intervals and titrated with sodium hydroxide using phenolphthalein as the indicator. Calculations were based on the difference of the titration at any time t in minutes and the titration at the end of 24 hours. When the reaction was completed, this difference was a measure of the concentration of ethyl acetate remaining unchanged or unhydrolyzed at time t. Each molecule of ethyl acetate that hydrolyzed produced one molecule of acetic acid, and the increase in acidity was a direct measure of the amount of ethyl acetate that had reacted. The amount of hydrochloric acid remained unchanged throughout the experiment. The concentrations of ethyl acetate calculated from the differences between the titration values and the final titration were arranged in tabular form. A graph was drawn on semilogarithmic paper by plotting the concentration of ethyl acetate, c, against time, t, in minutes and the best straight line through the points. Using the equation, - log c_A (k / 2,303) t+ constant, the specific reaction rate, k, was calculated by multiplying the slope of the line by 2.303. The activation energy, E, was calculated from the values of k at 19 ± 0.1°C and 30 ± 0.1°C using the equation, E = [2.303 log₁₀ k₂/k x R x T₁ x T₂] / [T₂ - T₁] where k₁ = specific reaction rate at 19 ± 0.1°C k₂ = specific reaction rate at 30 ± 0.1°C R = Constant T₁ = Absolute temperature for 19 ± 0.1°C T₂ = Absolute temperature for 30 ± 0.1°C The results of this investigation showed that the specific reaction rates were increased by ultrasonic irradiation of 400, 700, 1000, 1500 kc in the order of five percent for 20 minutes irradiation over the rates for 10 minutes irradiation. / Ph. D.

Made available in DSpace on 2017-07-25T19:29:37Z (GMT). No. of bitstreams: 1 melissa.pdf: 22685399 bytes, checksum: 52613e711bdb2207d8ee610ea5bcd520 (MD5) Previous issue date: 2006-08-10 / Trinexapac-ethyl is a growth reducer used in winter cereals that promote height plant reduction, preventing the lodging. With the aim of determine the rate and the time of ethyltrinexapac (Moddus) application in wheat cultivars of different lodging answers an experiment was established at the UEPG School Farm in Ponta Grossa, PR, in 2005, in a clay soil. The experimental design was complete randomized blocks, in a factorial design 2 x 2 x 6, with three repetitions for four wheat cultivars. The treatments consisted of two nitrogen rates (50 and 240 kg/ha), two times of trinexapac-ethyl application (between 1º and 2º knot and between 2º and 3º perceivable knot) and six trinexapac-ethyl rates (0; 31,2; 62,5; 93,7; 125,0 and 156,2 g/ha), applied in four wheat cultivars of different answers to the lodging (CD-104 - resistant), (Vanguarda - moderately resistant), (Supera - moderately susceptible) and (CEP-24 - susceptible). It evaluated agronomicals characteristics, diseases severity, yield components and yield. The nitrogen rate affected some plant characteristics and the yield for CEP-24. The application time of trinexapac-ethyl affect the yield of CD-104; the plant height that was lesser how much more delayed was the application in cultivars CEP-24 and CD-104; trinexapac-ethyl reduced the plants height of all the cultivars with changeable intensity with the port of the same ones. For all the cultivars the adjustment equation of the yield in relation to the trinexapac-ethyl rates was quadratic, occurring an increase of the yield with the increase of the reducer rate, until a changeable limit with the cultivar. However, for all cultivars occurred increase of the yield with the trinexapac-ethyl application. For the cultivar majority it had reduction of rust severity, head blight and foliar spots with the increase of the trinexapac-ethyl rate. / O trinexapac-ethyl é um redutor de crescimento utilizado em cereais de inverno que promove redução na altura das plantas, evitando o acamamento. Visando determinar a dose e a época de aplicação de trinexapac-ethyl (Moddus) em cultivares de trigo de diferentes respostas ao acamamento realizou-se um experimento na Fazenda Escola da Universidade Estadual de Ponta Grossa (UEPG), no ano de 2005, em um Cambissolo distrófico de textura argilosa. O delineamento experimental foi de blocos ao acaso, em esquema fatorial 2 x 2 x 6 com três repetições para quatro cultivares de trigo. Os tratamentos constaram de duas doses de nitrogênio (50 e 240 kg/ha), duas épocas de aplicação de trinexapac-ethyl (entre o 1º e o 2º nó e entre o 2º e o 3º nó perceptível) e de seis doses de trinexapac-ethyl (0; 31,2; 62,5; 93,7; 125,0 e 156,2 g/ha), aplicadas em quatro cultivares de trigo de diferentes respostas ao acamamento (CD-104 – resistente), (Vanguarda – moderadamente resistente), (Supera – moderadamente suscetível) e (CEP-24 – suscetível). Avaliou-se características agronômicas, severidade de doenças, componentes da produção e produtividade. As doses de nitrogênio afetaram algumas características da planta e a produtividade de apenas da cultivar CEP-24. A época de aplicação do trinexapac-ethyl afetou de forma substancial a produtividade apenas na CD-104; a altura das plantas foi menor quanto mais tardia foi a aplicação do redutor nas cultivares CEP-24 e CD-104; o trinexapac-ethyl reduziu a altura das plantas de todas as cultivares com intensidade variável com o porte das mesmas. Para todas as cultivares a equação de ajuste da produtividade em relação às doses de trinexapac-ethyl foi quadrática ocorrendo um aumento da produção com o aumento da dose do redutor, até um limite variável com a cultivar. No entanto, para todas as cultivares ocorreu aumento da produtividade com a aplicação do trinexapac-ethyl, e para a maioria delas houve redução da severidade de giberela e manchas foliares com o aumento da dose de trinexapac-ethyl.

The ability to generate chiral building blocks is of paramount importance to organic chemists. This problem presents itself most notably at the interface of chemistry and biology, where molecules of only a single enantiomer can induce function to many biological systems. In this context, recent developments in the field of organocatalysis, most notably the employment of chiral N-heterocyclic carbenes (NHCs) have shown much promise. Our group has recently shown that one possible chiral NHC catalyzed Stetter cyclization product of a conjugated triene, a highly functionalized cyclopentenone, contains both a chiral center and an adjacent conjugated diene. This structure can be easily elaborated to a bicyclic structural motif present in some biologically active natural products from the ginkgolide family, and is difficult to access by other means. The synthesis of novel vinyl stannanes and other coupling substrates involved in the development of the aforementioned reaction discovery are described in this report.

The hip-flask defence is a common claim in drunkdrinking cases. In Sweden and Norway two different models are used to determinethese cases. In Sweden one blood and two urine samples taken 60 minutes apartare used for analysis. In Norway two blood samples taken 30 minutes apart areused. Sweden focuses on the rise or fall of alcohol concentration in urine(UAC), and the ratio between UAC and blood alcohol concentrations (BAC). Norwayfocuses on the rise or fall of the alcohol metabolite ethylglucuronide (EtG) and the ratio between BAC and EtG. The aim of this study wasto test the models for multiple intakes and with different alcoholic beverages.Thirtyfive participants ingested two doses, first0.51 g/kg of beer and later either 0.25, 0.51 or 0.85 g/kg of beer, wine orvodka. Blood and urine samples were obtained before and after alcoholingestion. Alcohol was measured by GC-HS, and the alcohol metabolite byUPLC-MS/MS. The results showed that there are kineticdifferences between single and repeated intakes, that there are no significantdifferences in kinetics from different alcoholic beverages and thatthe Norwegian model appears to be the stronger one in hip-flask determination.

Submitted by Eunice Novais (enovais@uepg.br) on 2017-08-22T23:40:55Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Marina Senger.pdf: 1761600 bytes, checksum: 7e23e8f0e9c9b891e3c733edf20e817f (MD5) / Made available in DSpace on 2017-08-22T23:40:55Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Marina Senger.pdf: 1761600 bytes, checksum: 7e23e8f0e9c9b891e3c733edf20e817f (MD5) Previous issue date: 2017-04-28 / O trigo é um dos cereais mais importantes a nível mundial e é um alimento básico para cerca de um terço da população do mundo, fornecendo mais proteína do que qualquer outro cereal. O desafio global para a cadeia de produção do trigo é aumentar a produtividade de grãos e a qualidade industrial. A produtividade e a qualidade do trigo podem ser comprometidas por diversos fatores que ocorrem no campo, como modo de cultivo, manejo, acamamento e condições de clima e solo. Com o objetivo de avaliar o efeito de épocas de aplicação de nitrogênio em cobertura, densidades de semeadura e épocas de aplicação do regulador de crescimento e sua influência na produtividade e na qualidade industrial dos grãos, foram instalados doze experimentos, diferindo pelo manejo, cultivar e ano de cultivo, na Fazenda Escola da Universidade Estadual de Ponta Grossa, no município de Ponta Grossa, PR, região Campos Gerais, no ano de 2013 com repetição em 2014. O delineamento experimental utilizado nas diferentes épocas de aplicação de nitrogênio em cobertura, para cada cultivar (Gralha Azul e BRS-Pardela), foi de blocos ao acaso, com 6 tratamentos e 4 repetições. Os tratamentos constaram de seis épocas de aplicação de nitrogênio em cobertura, aos 0, 10, 20, 30, 40 e 50 dias após a semeadura. A dose utilizada foi de 100 kg ha-1 de N na forma de uréia (222 kg ha-1). O delineamento experimental utilizado nas diferentes densidades de semeadura, para cada cultivar (Gralha Azul e BRS-Pardela), foi de blocos ao acaso, com 6 tratamentos e 4 repetições. Os tratamentos constaram de seis densidades de semeadura, com 150, 300, 450, 600, 750 e 900 plantas por metro quadrado. O delineamento experimental utilizado nas diferentes épocas de aplicação do regulador de crescimento Trinexapac-ethyl, para cada cultivar (Gralha Azul e BRS-Pardela), foi de blocos ao acaso, com 4 tratamentos e 4 repetições. Os tratamentos constaram de três épocas de aplicação, no perfilhamento, entre o 1º e o 2º nó perceptível, entre o 2º e o 3º nó e testemunha. O sistema de cultivo utilizado foi o plantio direto na palha, sendo a soja a cultura antecessora nos dois anos de pesquisa. Na fase de antese foram avaliados o número de perfilhos; comprimento e largura das folhas e estatura da planta mãe. Na maturidade fisiológica foi avaliado o número de espigas por metro e de espiguetas por espigas; o número de grãos por espiga; massa de mil grãos e índice de colheita aparente. Quando os grãos atingiram o ponto de colheita foi estimado a produtividade e o índice de acamamento. Dos grãos colhidos foi determinado o peso hectolítrico (PH) e o Número de queda (NQ). Fundamentado nos resultados encontrados pode-se concluir que a aplicação de nitrogênio em cobertura na fase de perfilhamento proporcionou maior produtividade na cultura do trigo. A época de aplicação de N não afetou o PH e o NQ, visto que essa resposta também está relacionada com a interação da cultivar e as condições ambientais. As diferentes densidades de semeadura afetam a produtividade na cultura do trigo, sendo as melhores densidades aquelas que também são recomendadas pela pesquisa oficial. As diferentes densidades de semeadura não afetaram o PH e o NQ, e essa resposta também pode estar relacionada com a interação da cultivar e as condições ambientais. As épocas de aplicação de Trinexapac-ethyl não proporcionaram maior produtividade na cultura do trigo. A época de aplicação do regulador afetou os valores de PH apenas em um ano e não afetou os valores de NQ, essa resposta pode estar relacionada com a interação da cultivar e as condições ambientais. / Wheat is one of the world's most important cereals and is a staple food for about a third of the world's population, providing more protein than any other cereal. The overall challenge for the wheat production chain is to increase grain yield and industrial quality. Wheat yield and quality can be compromised by several factors that occur in the field, such as cultivation, management, lodging, and soil and climate conditions. In order to evaluate the effect of nitrogen application times on cover, seeding densities and application times of the growth regulator and the influence on grain yield and industrial quality, twelve experiments were carried out, differing in the management, cultivar and Year of cultivation, in the School Farm of the State University of Ponta Grossa, in the Ponta Grossa, PR, Campos Gerais, in the year 2013 with repetition in 2014. The experimental design used in the different times of nitrogen application in coverage, for each cultivar (Gralha Azul and BRS-Pardela) was randomized blocks with 6 treatments and 4 replicates. The treatments consisted of six times of nitrogen application in cover, at 0, 10, 20, 30, 40 and 50 days after sowing. The dose used was 100 kg ha-1 of N as urea (222 kg ha-1). The experimental design used in the different sowing densities, for each cultivar (Gralha Azul and BRS-Pardela), was randomized blocks with 6 treatments and 4 replicates. The treatments consisted of six sowing densities, with 150, 300, 450, 600, 750 and 900 plants per square meter. The experimental design used in the different application times of the Trinexapac-ethyl growth regulator for each cultivar (Gralha Azul and BRS-Pardela) was a randomized complete block with 4 treatments and 4 replicates. The treatments consisted of three application times, in the tillering, between the 1st and 2nd node perceptible, between the 2nd and 3rd node and control. The cultivation system used was no-till in the straw, and soybeans were the predecessor crop in the two years of research. In the anthesis phase, the number of tillers was evaluated; Length and width of the leaves and height of the mother plant. At physiological maturity, the number of ears per meter and spikelets per ear were evaluated; The number of grains per spike; Mass of one thousand grains and apparent harvest index. When the grains reached the harvest point, yield and lodging index were estimated. From the harvested grains, the hectolitric weight (PH) and Falling Number (NQ) were determined. Based on the results found, it can be concluded that the application of nitrogen under cover in the tillering phase provided higher productivity in the wheat crop. The time of N application did not affect the pH and NQ, since this response is also related to the interaction of the cultivar and the environmental conditions. The different sowing densities affect yield in the wheat crop, with the best densities being those recommended by official research. The different sowing densities did not affect the PH and the NQ, and this response could also be related to the interaction of the cultivar and the environmental conditions. The times of application of Trinexapac-ethyl did not provide greater yield in the wheat crop. The time of application of the regulator affected the values of PH only in one year and did not affect the values of NQ, this response could be related to the interaction of the cultivar and the environmental conditions.

Made available in DSpace on 2017-07-25T19:29:53Z (GMT). No. of bitstreams: 1 CAMILA FERREIRA.pdf: 1055676 bytes, checksum: d6ad9b268ad142d66ed7332d519cee2e (MD5) Previous issue date: 2012-07-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Increase the productive potential of agricultural crops with cultivation practices and management are some challenges of agricultural research in the face of growing demand for food. Accordingly, experiments were conducted with the aim to evaluate the effects of the growth regulator trinexapac-ethyl combined or not with modes of application of herbicides in corn. There were two distinct works, one evaluating the effects of trinexapac-ethyl at different doses and application times and another evaluating the consequences of desiccation or not the area in pre-seeding and application of methods of herbicides post-emergence combined or not the growth regulator, in two corn hybrids. In the season 2010/11 were carried out two experiments, one with the hybrid Status TL and the other with the Maximus TLTG,both in the experimental design of randomized blocks in factorial scheme 4 x 4 (trinexapac-ethyl applied at stages V2, V4, V6 and V8 corn, at doses of 0.0, 187.5, 375.0 and 562.5 g ha-1). The results showed that the time of application did not affect the morphological characteristics of both hybrids, at the dose of the regulator, to the Status TL no material effect on the measured characteristics, but for the Maximus TLTG, increasing the dose of the product resulted in an increased width and decrease in length of the sheet above the ear, with no effect on components of production and productivity. In the season 2010/11 and 2011/12, there were two experiments in each year, in a randomized block design in a factorial 2 x 2 x 2, with treatments consisting of desiccation or not the day of seeding, the unique application sequential or post-emergence herbicides, in combination with atrazine and mesotrione for hybrid Status TL and glyphosate to Maximus TLTG, besides the application or not a growth regulator, trinexapac-ethyl in combination with postemergence herbicides. Desiccation in two seasons on the day of seeding resulted in greater productivity for the Maximus TLTG. The productivity of Status TL increased with desiccation in pre-sowing only in 2010/11 crop. The mode of application of herbicides post-emergence changed some yield components of hybrid Status TL in 2010/11 crop. The application of trinexapac-ethyl did not affect substantially the characteristics of the hybrids in two seasons. / Aumentar o potencial produtivo das culturas agrícolas através de práticas de cultivo e manejo são alguns desafios da pesquisa agronômica diante da crescente demanda por alimentos. Nesse sentido, realizaram-se experimentos com o objetivo de avaliar os efeitos do regulador de crescimento trinexapac-ethyl combinado ou não a modos de aplicação de herbicidas na cultura do milho. Foram realizados dois trabalhos distintos, sendo um avaliando os efeitos do trinexapac-ethyl em diferentes doses e épocas de aplicação e outro avaliando as consequências da dessecação ou não da área em pré-semeadura e de modos de aplicação de herbicidas em pósemergência combinados ou não ao regulador de crescimento, em dois híbridos de milho. Na safra 2010/11 foram realizados dois experimentos, um com o híbrido Status TL e o outro o Maximus TLTG, sendo ambos no delineamento experimental de blocos ao acaso em esquema fatorial 4 x 4 (trinexapac-ethyl aplicado nos estádios V2, V4, V6 e V8 do milho, nas doses de 0,0, 187,5, 375,0 e 562,5 g ha-1). Os resultados mostraram que a época de aplicação não afetou as características morfológicas de ambos os híbridos e, em relação à dose do regulador, para o Status TL não houve efeito relevante sobre as características avaliadas, mas para o Maximus TLTG, o aumento da dose do produto resultou em aumento da largura e diminuição do comprimento da folha acima da espiga, sem efeitos na produtividade e seus componentes. Na safra 2010/11 e na 2011/12, realizaram-se dois experimentos em cada ano, no delineamento de blocos ao acaso em esquema fatorial 2 x 2 x 2, cujos tratamentos constaram da dessecação ou não no dia da semeadura, da aplicação única ou sequencial de herbicidas em pós-emergência, mesotriona combinado com atrazina para o híbrido Status TL e glifosato para o Maximus TLTG, além da aplicação ou não do regulador de crescimento trinexapacethyl em combinação aos herbicidas em pós-emergência. Nas duas safras a dessecação no dia da semeadura resultou em maiores produtividades para o Maximus TLTG. A produtividade do Status TL aumentou com a dessecação em présemeadura somente na safra 2010/11. O modo de aplicação dos herbicidas em pósemergência alterou alguns componentes de rend mento do híbrido Status TL na safra 2010/11. A aplicação do trinexapac-ethyl não afetou de forma substancial as características dos híbridos nas duas safras.

Made available in DSpace on 2017-07-25T19:30:46Z (GMT). No. of bitstreams: 1 Allan Christian de Souza.pdf: 1299031 bytes, checksum: 95fdaaa95883f295a49305c261ae0342 (MD5) Previous issue date: 2014-09-25 / The wheat quality and yield may be limited or compromised by several factors in the field, being the climatic the main by factor at the end of the crop cycle. Aiming to determine whether different harvest time combined or not with plant growth regulator application affect crop yield and wheat grain quality, four experiments were conducted, differing by cultivars type and sowing time, at Ponta Grossa city, PR, in 2013. The experimental design used in the first time for both cultivars BRS-Pardela and Quartzo) were randomized blocks, at factorial scheme (2 x 5), with our without growth regulator applications and five grain moisture contents (30, 25, 20, 15 and 13%), being four replications. The experimental design for the second time for both cultivars were randomized blocks with five grain moisture content at harvest time (30, 25, 20, 15 and 13%) being 4 replications. For the first harvesting time the growth regulator application resulted in lower thousand grain weight only for cultivate BRS-Pardela and did not affect the yield, yield components as well the industrial quality for both wheat cultivars. The different harvesting times had no effect in either yield, Falling Number (FN) or hectoliter weight (PH) for both cultivars. In the second sowing time the production components and productivity for both cultivars were not affected by the different harvest time. A linear and quadratic decrease on the PH with the delaying of harvest time was noticed for BRS-Pardela and Quartz, respectively, for the FN only the BRS-Pardela showed quadratic reduction delaying the harvest time. Keywords: Triticum aestivum; No-tillage; harvest time; industrial quality, trinexapac-ethyl. / A produtividade e a qualidade do trigo podem ser limitadas ou comprometidas por diversos fatores que a cultura sofre no campo, principalmente pelas condições climáticas no final do ciclo. Com o objetivo de determinar se diferentes épocas de colheita combinadas ou não com regulador de crescimento afetam a produtividade e qualidade dos grãos de trigo, realizaram-se quatro experimentos, diferindo pela cultivar e época de semeadura, no município de Ponta Grossa, PR, no ano de 2013. O delineamento experimental utilizado na primeira época de semeadura para as duas cultivares (BRS-Pardela e Quartzo) foi o de blocos ao acaso, em esquema fatorial (2 x 5), aplicação ou não do regulador de crescimento (na dose de 400 ml/ha do produto comercial) e cinco teores de umidade do grão na colheita (30, 25, 20, 15 e 13%), com 4 repetições. O delineamento experimental para a segunda época para as duas cultivares foi de blocos ao acaso, com 5 teores de umidade do grão na colheita (30, 25, 20, 15 e 13%) e 4 repetições. Para a primeira época a aplicação do regulador de crescimento resultou em menor massa de mil grãos apenas para a cultivar BRS-Pardela e não afetou os outros componentes de produção, produtividade e qualidade industrial das duas cultivares de trigo. As épocas de colheita não afetaram a produtividade, o Falling Number (FN) e o peso hectolitro (PH) das duas cultivares. Na segunda época de semeadura as diferentes épocas de colheita não afetaram os componentes de produção e produtividade das duas cultivares. O PH diminuiu de forma linear com o atraso da época de colheita para a BRS-Pardela e quadrática para Quartzo e o FN de forma quadrática apenas na cultivar BRS-Pardela. Portanto concluo que.

The synthesis of p-lactams has been of foremost importance since the discovery of penicillin by Sir Alexander Fleming, in 1928, and its susequent structure elucidation in 1945. Ethyl N-2-bromo-alkylcarbamates show considerable potential as precursors to p- lactams. In the past, p-lactams have been prepared by many methods, none of which have involved 2-3 bond formation. The proposed ring closure using ethyl N-2-bromoalkylcarbamate involves 2-3 bond formation, making this method of synthesis novel. This work describes two attempted methods of cyclisation. The first using a Grignard reagent, and the second, using abstraction of an acidic proton a to a phosphonate group. These methods of intramolecular cyclisation were based on analogous intermolecular additions, which are also described. The second method was also used to determine the general potential of ethyl N-bromo- alkylcarbamtes as precursors to other heterocyclic systems. / Thesis (M.Sc.)-University of Natal, Durban, 2001. / NRF & NRF/DEA & T.

A 1H, 13C, and 6Li NMR study of 2-ethylhexyllithium showed that 2- ethylhexyllithium exists solely as a hexamer in cyclopentane solution over the temperature range from 25 to -65 °C. Furthermore, 2-ethylhexyllithium and lithium 2- ethyl-1-hexoxide were shown to form mixed aggregates when the alkoxide was formed in situ by reacting 2-ethylhexyllithium with 2-ethyl-1-hexanol. A multinuclear, variable temperature NMR study of a sample with an O:Li ratio of 0.2 led to the identification of at least four such aggregates, one of which was found to be a hexamer with the composition R5(RO)Li6. Studies of samples with higher O:Li ratios, up to 0.8, showed additional mixed aggregates present. All solutions containing mixed aggregates were also shown to contain hydrocarbon soluble lithium hydride. A study of lithium 2-ethyl-1- hexoxide indicated that it aggregates in solution as well.